On Law and Order: Special Victims Unit, Mariska Hargitay (as Lieutenant Olivia Benson) has worked tirelessly to get justice for the hundreds of sexual assault and rape survivors who have entered Manhattan's Special Victims Unit. In real life, Hargitay fights for survivors, too, by bringing attention to the hundreds of thousands of untested rape kits in police evidence rooms across the country.

Hargitay both produced and appears in the upcoming HBO documentary I Am Evidence, which aims to take a closer look at the problem of nearly 175,000 untested rape kits that have been uncovered throughout the country, according to End the Backlog. By focusing on both victims' accounts and the work of people like Kym Worthy, a Michigan county prosecutor who has pledged to test each of Detroit's 11,000 rape kits, the documentary hopes to combat this endemic problem.

"I've been playing Detective Benson on SVU for 15 years, and when I first began, letters started coming in from viewers," Hargitay says in a clip from the documentary provided to People. "These men and women were disclosing to me their stories of abuse. And, at first, it was a few, then it was more, then it was hundreds, and then it was thousands. A majority of them included some version of, 'I've never told this to anybody before.' And here I was an actress on a TV show getting these letters and I was immersed in these issues, so I educated myself and I got involved. To me, the rape kit backlog is the clearest and the most shocking demonstration of how we regard these crimes."

Despite the staggering volume of rape kits that go untested across the country, little attention is paid to the issue—a reality that Hargitay, Worthy, and others featured in the documentary are hoping to change.

"A lot of people just don't know about this problem and I was one of those people," Hargitay says in the clip.

"I had absolutely no clue that people stockpile rape kits," Worthy says.

The documentary, which is set to premiere April 24 at the Tribeca Film Festival, isn't the first time that Hargitay has worked on behalf of survivors of sexual assault and rape. In 2004, she founded the Joyful Heart Foundation to provide support to survivors of domestic violence, sexual assault, and child abuse. The organization has since directly helped more than 18,500 survivors get the help and support they need. End the Backlog, a non-profit, is a program of the Joyful Heart Foundation that's focused on healing, educating, and empowering survivors of sexual assault, domestic violence and child abuse. The Joyful Heart Foundation is the lead social action campaign partner for I Am Evidence.

If you or someone you know has been sexually assaulted, you can call the National Sexual Assault Hotline at 800-656-HOPE (4673). More resources are available online from the National Sexual Violence Resource Center.